Determination of safety performance function for pedestrians and cyclists

Abstract

A road traffic accident is an accident occurring or originating on the street open to public traffic, resulting in one or more persons being injured or killed and involving at least one moving vehicle. Out of these road traffic accidents unprotected road user accidents that is both pedestrians and cyclists involved in accidents make a big contribution to the accident statistics. In Sri Lanka, major proportion of accident victims is pedestrians and cyclists who also constitute the majority of road users. In year 1999, there were 6 485 pedestrian accidents and2753 bicycle accidents. According to the police accident statistics 33% and 12% of total accident casualties were pedestrians and cyclists respectively. Therefore, it is imperative to give more emphasis to bring down the unprotected road user accidents in Sri Lanka. Since there are so many places with unprotected road user accidents in the country, it is necessary to select the locations with more severe road safety problems. In order to identify such locations there are three mechanisms used in this research considering the number of accidents, severity of accidents and the traffic flow. The indicators used are the number of accidents, equivalent accident number (EAN) and the accident rate (AR). The safety performance functions for pedestrians and cyclists have been developed considering the selected indicators. The limits for the EAN per accident and AR have been determined in order to select the accident blacks pots for safety improvements giving prominence to the unprotected road user accidents. These limits can be revised in future as the road safety improves, in the country. This research also includes the assessment of pedestrian crossing as a safety feature. This study revealed that the marked zebra crossings do not offer a well safe place for the pedestrians to cross the road. Therefore, more and more pelican crossings and other safety features around the pedestrian crosswalks should be introduced to improve the pedestrian behavior and the driver compliance. Analysis of unprotected road user/ motor vehicle crashes help to establish engineering, education and enforcement solutions. It is proposed that, although educational and enforcement counter measures may serve to increase safe cycling and walking, they are likely to provide benefit only in the short terMEngineering countermeasures. that focus on changing the road environment to give cyclists and pedestrians their own space are imperative to increase safe cycling and walking in long term. In this analysis, it was suggested suitable engineering countermeasures for unprotected road users at selected black spot locations corresponding to the observed safety problems.